Tension device for straw-sewing machines.



Nu 670,078. Patented Mar.|9,l90L

G.HUMPHREY. TENSIUN DEVICE FOR STRAW SEWING MACHINES.

Application filed June 12, 1897.)

(No Model.)

Uwrrnn STATES GEORGE HUMPHREY, OF ST. ALBANS, ENGLAND.

TENSION DEVICE FOR STRAW-SEWING MACHINES.

SPEGIFIGATION formingpart of Letters Patent No. 670,078, dated March 19, 1901.

Application filed June 12, 1897. Serial No. 640,588. \No model.)

To all whom, it may concern:

Be it known that I, GEORGE HUMPHREY, engineer, asubject of the Queen of Great Britain and Ireland, residing at 22 St.Peters street, St. Albans, England, have invented certain new and useful Improvements in Machines for Sewing Straw Plait and Like Materials, of which the following is a specification.

This invention relates to a thread-controlling device for use in machines for sewing straw plait and like material.

The object of the invention is to supply the thread in an even manner without throwing undue strain on it in drawing it through the work, and for this purpose the thread is lifted toward and withdrawn from the needles at each stitch and released at certain intervals.

The device consists of two disks, as in ordinary tension apparatus, which are mounted on a rocking arm actuated in two directions by cams upon the main shaft.

The drawings only show such parts of the apparatus as are necessary for the understand ing of my invention.

Figure l is a sectional view of my threadcontrolling device. Fig. 2 is an elevation, partly in section, at right angles to Fig. 1; and Fig. 3 is a plan of the same.

A is the main shaft of the straw-plait-sewing machine, this shaft eXtendingin the usual manner from end to end. Upon this shaft are fixed the two cams B and C, the cam B (shown more especially in Fig. 1) having the two cam-surfaces b a short distance from each other, so that on turning the shaft they operate at a short interval, leaving a second interval of about half a revolution before the next double operation. The cam-disk O is of greater thickness and is formed with the camslot 0 in its periphery, this slot extending completely around it and giving a motion at rightangles to the cam B.

The front of the machine-case D (shown in section in Fig. l) carries the pin E, which is free to turn, and to this pin is pivoted at e the rocking arm F, carrying at its upper end the roller f, which bears upon the periphery of the cam B. The cam B as it revolves turns the rocking lever F around the pivot e, giving it a motion transverse to the main shaft A. The rocking lever F is also provided with an extension f, having at its end a second roller f which extends into the slot 0 in the cam 0. As the second cam revolves together with the first the cam-slot turns the rocking lever, together with the pin E, giving the rocking lever a motion longitudinal to the main shaft and at right angles to that due to the cam B.

Through a slot 61 in the front D of the machine-case a pin G is passed, and upon this pin the tension-disks H are fitted, and an adjusting-nut g regulates the tension against the pressure of the spring g. To a forked extension of this pin, formed for convenience in a separate piece, is connected at g the rocking arm F, which transmits to the tension-disks the transverse and longitudinal motion due to the two cams.

The transverse motions due to the cam B serve to grip and. release the thread, the camsurfaces 1) when they meet the roller upon the rocking arm opening the tension-disks H, which close again upon the thread as the roller passses to the concentric portions of the cam.

The longitudinal to-and-fro motion dueto the cam'O causes the whole tension mechanism to move in the slot d.

The mannerin which the stitch is formed in the machines of the description to which this invention relates is well known and does not require special descriptionl The action of the thread-controlling device is as follows: At the beginning of the upward stroke of the needles the thread is held between the disks, the device acting as a tension. When the needles begin to pass through the work, the thread is released by the cam B; but immediately the needles have passed through the thread is again gripped and for the remainder of the stroke the thread is held by the tension. It is necessary to release the thread at the moment it is being drawn through the straw plait, as if held by the tension it is liable to break. Immediately the needles begin their down ward stroke the thread is again released by the cam B and is thus allowed to form the loop as the needles descend. After about a quarter of the downward stroke the thread is again gripped by the disks H and at the same time the cam E causes the disks to be drawn back, the device then acting as a take-up for the slack thread. The thread is still gripped for part of the forward movement of the disks caused by the cam C, so that the thread is fed forward by this cam ready to be drawn up by the needles.

hat I claim as my invention, and desire to secure by Letters Patent, is-- 1. In a plait or braid sewing machine the combination with the main shaft thereof, a rocking arm and tension-disks carried by the said arm, of two cams one adapted to oscillate the said rocking arm longitudinally to the main shaft of the apparatus and the other to oscillate the rocking arm transversely to the said shaft and to open the tension-disks at certain intervals, the longitudinal motion servin g to feed the thread forward and to take up the slack thread, substantially as described and for the purposes specified.

2. In a plait or braid sewing machine the combination with the main shaft thereof, a rocking arm and tension-disks carried by the said arm, of two cams, one adapted to oscillate the rocking arm longitudinally to the main shaft of the apparatus and the other having two camsurfaces which oscillate the rocking arm transversely to the said shaft and open the tension-disks twice at each revolution of the main shaft, substantially as described and for the purposes specified.

3. In a plait or braid sewing machine, the combination with the main shaft thereof, of the rocking arm F, the pin G fitted to the rocking arm, and the gripping-disks H, the disks G carried by said shaft and having a cam-slot, the extension f carrying a rollerf projecting into said canrslot, a roller fearried by said arm and the cam B mounted on said shaft, the cam and cam-slot oscillating the rocking arm transversely and longitudinally to the main shaft of the apparatus, substantially as described and shown and for the purposes specified.

In witness whereof I have hereunto set my hand in the presenceof two witnesses.

GEORGE I'IUMPHREY.

In presence of- ALBERT EDWARD ELLEN, FRANK WILLIAM PATTISON. 

